package com.sicheng.蓝桥.练习题;

/**
 * @author zsc
 * @version 1.0
 * @date 2022/1/20 10:50
 */
public class 纯质数 {
    public static void main(String[] args) {
        int count = 0;
        boolean flag = false;
        for (int i = 2; i < 20210605; i++) {

            String s = i + "";
            for (int j = 0; j < s.length(); j++) {
                int temp = s.charAt(j) - '0';
                if (temp == 2 || temp == 3 || temp == 5 || temp == 7) {
                    flag = true;
                } else {
                    flag = false;
                    break;
                }

            }
            if (flag)
                count++;
        }
        System.out.println(count);
    }
}
